BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a partial cross sectional view of an end of a coaxial cable;
FIG. 1B shows the cable of FIG. 1A with outer cable components removed to expose the braid and the center conductor;
FIG. 1C shows the cable of FIG. 1B with the braid folded back over the jacket;
FIG. 2 is a partial cross sectional view of a coaxial connector connected to a cable prepared according to a known method;
FIGS. 3A-3C are partial cross sectional views of a coaxial cable illustrating the cable preparation method according to one embodiment of the present invention;
FIG. 4 is a cross sectional view of the components for a coaxial cable connector according to one embodiment of the present invention;
FIG. 5 is a cross sectional view of the components of the coaxial connector of FIG. 4 partially installed on a coaxial cable prepared according to a method disclosed herein;
FIG. 6 is a cross sectional view of the coaxial cable connector of FIG. 4 fully installed on the coaxial cable, shown in partial cross-section;
FIG. 6A is a cross sectional view of an alternative embodiment of the coaxial cable connector of FIG. 6 fully installed on the coaxial cable;
FIG. 7 is a cross sectional view of components for an alternative embodiment of a coaxial cable connector according to the present invention;
FIG. 8 is a cross sectional view of the components of the coaxial connector of FIG. 7 partially installed on a coaxial cable prepared according to a method disclosed herein; and
FIG. 9 is a cross sectional view of the coaxial connector of FIG. 7 fully installed on the coaxial cable.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the present preferred embodiment(s) of the invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts.
FIGS. 3A-3C are partial cutaway views along the centerline of a coaxial cable illustrating the cable preparation method as disclosed herein. FIG. 3A shows cable 100 comprising center conductor 101, dielectric 102, outer conductor or shield 103, braid 104, and jacket 105. For some embodiments, such as a coaxial cable jumper, a desired length of cable 100 is cut, preferably making a clean cut. Referring to FIG. 3B with a desired length of cable 100, the cable preparation includes removing a portion of the protective layer 105, a portion of the braid 104, and a portion of the dielectric 102 from the end of the coaxial cable to provide a prepared end of the cable, which can be effected using one or more known tools, wherein the prepared end comprises: a protective layer cut edge 110; a protruding portion of the braid 104 that protrudes a length X from the cut edge 110 of the protective layer 105, a protruding portion of the dielectric 102 that protrudes a length Y from the cut edge 110 of the protective layer 105, and a protruding portion of the inner conductor 101 that protrudes a length Z from the cut edge 110 of the protective layer 105, wherein the ratio of X/Y is less than 1, preferably less than 0.5, more preferably less than 0.25. Thus, the cable preparation includes removing outer components of the cable 100, such as dielectric 102, outer conductor or shield 103, braid 104, and/or jacket 105, as appropriate, to expose a length A of the center conductor 101, and to expose a length B of the shield 103, and to expose a length C of the braid 103, wherein the shield 103 and dielectric protrude beyond the end of the cable jacket 105 for a length D, where D=B+C, and the tip of the center conductor is disposed a length E away from the end of the cable jacket 105, where E=A+B+C=A+D, wherein the ratio of C/B is less than 1, preferably less than 0.5, more preferably less than 0.25. In some embodiments, the method further comprises the step of lifting at least a portion of the exposed length C of braid 104 radially outwardly, e.g. away from shield 103, preferably toward the end of jacket 105. In some embodiments, the lifting comprises flaring at least a portion of the exposed length C of braid 104 away from shield 103, for example by applying a tool having a conically tapered portion to the cable 100 and under exposed length C, or by applying part of the connector to the cable during connection of the connector onto the cable.
Even if desired dimensions for cable preparation disclosed herein are not readily achievable by use of industry standard available tooling intended for use in the field by a single installer, such desired dimension can be easily achieved by high speed factory production tooling.
Referring to FIG. 4, the coaxial cable connector 10 comprises a tubular shell 20, a coupler 30, and a tubular post 40. The tubular shell 20 is preferably made from metal and plated with a non-corrosive material such as nickel. Alternatively, tubular shell 20 can be constructed from an engineering polymer, such as polyamides (e.g. nylon), polyesters, polyimides, and/or polysulfones. Coupler 30 is preferably made from a conductive material such as brass and is plated with a corrosion resistant material such as nickel. Alternatively, coupler 30 may be constructed from an engineering polymer. Tubular post 40 is preferably made from electrically conductive material, such as brass, and is preferably plated with a conductive material such as tin.
In some embodiments, the braid 104 is flared by a tool, or by angled surface 46 of post 40 which is driven under the braid 104 thereby further reducing cable preparation time and effort. Thus, folding back of braid 104 over the outside of the jacket 105 as found in known cable preparation methods is eliminated, thereby reducing the amount of skill and time to prepare the cable.
As seen in FIG. 4, tubular shell 20 is generally tubular and comprises outer surface 21, front end 23, back end 24, and an internal surface 22 defining internal bore 26 that extends between front and back ends 23, 24. It should be noted that the outer surface 21, the internal surface 22 or both the internal and the outer surfaces of shell 20 can have more than one diameter or shape as is illustrated in FIG. 4. It is also possible that the outer surface 21 and the internal surface 22 also have constant diameter portions over the entire length of shell 20. Internal surface 22 preferably has an internal chamfer 25 located adjacent back end 24 to assist the coaxial cable to enter the internal bore 26. Preferably, outwardly projecting annular rib 27 is disposed at the front end 23 forming backward facing annular face 28. As illustrated and discussed below in conjunction with FIG. 6A, the annular rib 27 need not be present on tubular shell 20.
Coupler 30 includes a back end 31, a front end 32, and an internal surface 33 defining internal bore 34. The coupler 30 shown in FIG. 4 is in the form of a coupling nut, wherein internal surface 33 includes an internal chamfer 35, an inwardly projecting annular ridge 36, internal threads 37, and an internal recess 38. The reduced diameter of annular ridge 36 defines a reduced diameter through-bore section 39 of internal bore 34. The increased diameter of internal recess 38 defines an increased diameter through-bore section 33 of internal bore 34. Coupler 30 may also take other forms in other embodiments.
Tubular post 40 is generally tubular and comprises back end 41, front end 42, outer surface 43, and internal surface 44 defining through-bore 45. It should also be noted that internal surface 44 and/or outer surface 43 can have differing diameters or shapes. Back end 41 of tubular post 40 is configured to be inserted into the end of the cable 100 preferably between braid 104 and shield 103. Front end 42 is adapted to engage shell 20, or alternately, partially engage coupler 30. The outer surface 43 of tubular post 40, as shown in FIG. 4, preferably includes an external tapered area 46 adjacent back end 41 leading to a first surface 47 preferably of constant diameter and an external annular face 48. A reduced diameter portion 50 is disposed between the annular face 48 and a first rearward-facing tapered portion 49. The reduced diameter portion 50 and annular face 48, as described below in more detail, assist in securing the jacket 105 and braid 104 within the coaxial cable connector 10. The tubular post 40 also preferably includes a constant diameter portion 51 between the first rearward-facing tapered portion 49 and a second rearward-facing tapered portion 52. A longer second surface 53 preferably of constant diameter extends between the second rearward-facing tapered portion 52 and a rearward facing annular surface 54 created by annular rib 55. The internal surface 44 of post 40 shown in FIG. 4 preferably comprises an inwardly projecting lip 56 which defines a reduced diameter through-bore portion of internal bore 45. In some embodiments, the angled surface of external tapered area 46 can be used to engage exposed length C of braid 104 as the post 40 and cable 100, preferably are driven together during assembly in order to lift at least a portion of exposed length C radially outward. Tubular post 40 may also take other forms in other embodiments.
FIG. 5 shows a side cutaway view of coaxial cable connector 10 partially installed on coaxial cable 100. Preferably, coupler 30 is first installed over the tubular shell 20 and then both coupler 30 and tubular shell 20 are installed over prepared cable 100 together. However, coupler 30 may first be installed over the prepared cable 100 and then tubular shell 20 is installed over the prepared cable 100. After the tubular shell 20 and the coupler 30 are installed on the prepared cable 100, back end 41 of post 40 is then inserted into cable 100 between the shield and the braid. In the embodiment shown in FIG. 5, coupler 30 is capable of rotating around the tubular shell 20, that is, the diametral relationship of outer surface 21 and bore 34 allows coupler 30 to rotate about shell 20 when coupler 30 is disposed about the tubular shell 20. Forward movement of coupler 30 relative to tubular shell 20 is restrained by engagement of annular rib 27 and backward facing annular face 28 with the reduced portion 39, thereby preventing coupler 30 from falling off from the front end 23 of shell 20.
In use, the end of coaxial cable 100 is brought together with tubular post 40, i.e. the back end 41 of tubular post 40, such that the cable outer conductor 103, dielectric 102 and center conductor 101 enter bore 44 of tubular post 40 such that cable 100 is impaled upon back end 41 of tubular post 40. In the embodiment shown in FIG. 5, the back end 41, external tapered area 46, the first surface 47, an external annular face 48, and reduced diameter portion 50 of tubular post 40 are driven between braided shield 104 and the outer conductor 103 of cable 100, preferably until the dielectric 102 at the end of the cable 100 is flush with the front end 42 of tubular post 40. Cable trim length as illustrated indicated in FIG. 3B is such that flared portion of cable braid 104 is forced into contact with, and may be shaped by, tapered portion 49 of tubular post 40. In this embodiment, a small protuberance of braid 104 extends radially outwardly and axially forwardly beyond tapered portion 49.
Referring to FIG. 6 which shows the connection between coaxial cable connector 10 and the cable 100 in the completed, i.e. fully installed or fully compressed, state, wherein the tubular shell 20 is advanced axially forward to (i.e. toward the post 40) surround at least a part of tubular post 40 and cable 100. No further crimping or manipulation is required after tubular shell 20 is fully advanced. Upon advancement of the tubular shell 20, jacket 105 and braid 104 are preferably sandwiched between the tubular shell 20 and the tubular post 40, shown in FIG. 6 where internal surface 22 and first surface 47 of the outer surface 43 of tubular post 40 sandwich jacket 105 and braid 104. In some embodiments, a portion of braid 104 is disposed in an annular cavity formed between the inner surface of the tubular shell 20 and the outer surface of tubular post 40, and preferably seized therebetween, for example as seen in the annular cavity 57 shown in the embodiment of FIG. 6. Trapping and seizing of braid 104 within such annular cavity as cavity 57 can provide additional and improved electrical grounding and improved mechanical retention of braid 104 thereby improving electrical and mechanical communication between cable 100 and coaxial cable connector 10. When the connector in embodiments such as shown in FIG. 6 is fully installed on cable 100, rearward axial movement of coupler 30 may or may not be limited. Lip 56 can serve to both position (for example, center) and restrain further axial movement of cable dielectric 102 with respect to the tubular post 40.
An alternative coaxial cable connector 10′ is illustrated in FIG. 6A. The coaxial cable connector 10′ is the same as coaxial cable connector 10 except that the tubular shell 20′ has a smooth front end 23′, i.e constant inner and outer diameters, and does not have the outwardly projecting annular rib 27 forming backward facing annular face 28 of the prior embodiment. As such, the inwardly projecting annular ridge 36 (and the reduced portion 39) of the coupler 30 engages the rearward facing annular surface 54 created by the annular rib 55 of the tubular post 40.
As seen in FIG. 7, another embodiment of a coaxial cable connector 210 comprises a tubular shell 220, a coupler 250, and a tubular post 290. The tubular shell 220 is preferably made from metal such as brass and preferably plated with a non-corrosive material such as nickel. Alternatively, tubular shell 220 can be constructed from an engineering polymer, such as polyamides (e.g. nylon), polyesters, polyimides, and/or polysulfones. Coupler 250 is preferably made from an electrically conductive material such as brass and is preferably plated with a corrosion resistant material such as nickel. Alternatively, coupler 250 may be constructed from an engineering polymer. Tubular post 290 is preferably made from conductive material, such as brass, and is preferably plated with a conductive material such as tin.
As seen in FIG. 7, tubular shell 220 is generally tubular and comprises outer surface 221, front end 223, back end 224, and an internal surface 222 defining internal bore 226 that extends between front and back ends 223,224. It should be noted that the outer surface 221, the internal surface 222 or both the internal and the outer surfaces of shell 220 can have more than one diameter or shape as is illustrated in FIG. 7. It is also possible that the outer surface 221 and the internal surface 222 also have constant diameter portions. Internal surface 222 preferably has an internal chamfer 225 located adjacent back end 224 to assist the coaxial cable to enter the internal bore 226. The internal surface 222 also preferably has a transition portion 227 that provides for a slightly larger diameter internal bore portion 228 adjacent the front end 223. Preferably a deformable lip 229 is disposed at front end 223 that forms a rearward facing surface 230. As explained in more detail below, the deformable lip 229 is expanded radially outward by the tubular post 290 to engage an annular recess in the coupler 250. An annular groove 231 is disposed in the outer surface 221 making a forward facing surface 232. An external, forward facing tapered surface 233 is positioned between the annular groove 231 and the rearward facing surface 230 formed by the deformable lip 229.
Coupler 250 includes a back end 251, a front end 252, and an internal surface 253 defining internal bore 254. The coupler 250 shown in FIG. 7 is in the form of a coupling nut, wherein internal surface 253 preferably comprises an internal chamfer 255, an inwardly projecting annular ridge 256, internal threads 257, and an internal recess 258. The reduced diameter of annular ridge 256 defines a reduced diameter through-bore section 259 of internal bore 254. The increased diameter of internal recess 258 defines an increased diameter through-bore section 253 of internal bore 254. Internal surface 253 preferably comprises an annular recess 260 and a frontward facing surface 261. Coupler 250 may also take other forms in other embodiments.
Tubular post 280 is generally tubular and comprises back end 281, front end 282, outer surface 283, and internal surface 284 defining through-bore 285. It should also be noted that internal surface 284 and/or outer surface 283 can have differing diameters or shapes. Back end 281 of tubular post 280 is configured to be inserted into the end of the cable 100 and preferably between braid 104 and shield 103. Front end 282 is adapted to engage shell 220, or alternately, partially engage coupler 250. The outer surface 283 of post 280, as shown in FIG. 7, preferably includes an external tapered area 286 adjacent back end 281 leading to a first surface 287 preferably of constant diameter and an external annular forward-facing surface 288. The annular forward-facing surface 288 and a first rearward-facing tapered portion 289 define a reduced diameter portion 290. The reduced diameter portion 290 and annular forward-facing surface 288, as described below in more detail, assist in securing the jacket 105 and braid 104 within the coaxial cable connector 210. The tubular post 280 also includes a second portion 291, preferably of constant diameter, between the first rearward-facing tapered portion 289 and a second rearward-facing tapered portion 292. A third surface 293, preferably of constant diameter, extends between the second rearward-facing tapered portion 292 and a third rearward facing tapered portion 297, which is adjacent to the rearward facing surface 294 created by annular rib 295. The internal surface 284 of post 280 shown in FIG. 7 preferably comprises an inwardly projecting lip 296 which defines a reduced diameter through-bore portion of internal bore 285. The angled surface of external tapered area 286 can be used to engage exposed length C of braid 104 as the cable as post 280 and cable 100 are driven together during assembly in order to lift at least a portion of exposed length C radially outward. Tubular post 280 may also take other forms in other embodiments.
FIG. 8 shows a partial cross sectional view of coaxial cable connector 210 partially installed on the coaxial cable. Tubular shell 220 is installed over prepared cable 100. Coupler 250 is installed over the tubular shell 220 either before or after the tubular shell 220 is installed on the prepared cable 100. After the tubular shell 220 and coupler 250 are installed on cable 100, back end 281 of tubular post 280 is then inserted into cable 100 between the shield and the braid. In the embodiment shown in FIG. 8, coupler 250 is capable of rotating around the tubular shell 220, that is, the diametral relationship of outer surface of the tubular shell 220 and bore 254 of the coupler 250 allows coupler 250 to rotate about shell 220 when coupler 250 is disposed about the tubular shell 220. Rearward movement of coupler 250 relative to shell 220 is restrained by engagement of forward facing surface 232 of the tubular shell 220 and the back end 251 of the coupler 250, thereby preventing coupler 250 from sliding backward toward the coaxial cable 100 and off the tubular shell 220. As described in more detail below, the deformable lip 229 will be moved radially outward by the tubular post 280 to engage the coupler 250 to prevent it from moving forward and slipping off of the tubular shell 250 in an axially forward direction.
In use, the end of coaxial cable 100 is brought together with tubular post 280, i.e. the back end 281 of tubular post 280, such that the cable outer conductor 103, dielectric 102 and center conductor 101 enter bore 285 of tubular post 280 such that cable 100 is impaled upon back end 281 of tubular post 280. In the embodiment shown in FIG. 8, the back end 281, external tapered area 286, the first surface 287, an external annular forward-facing surface 288, and reduced diameter portion 290 of tubular post 280 are driven between braided shield 104 and the outer conductor 103 of cable 100, preferably until the dielectric 102 at the end of the cable 100 is flush with the front end 282 of tubular post 280. Cable trim length as illustrated in FIG. 3B is such that flared portion of cable braid 104 is forced into contact with, and may be shaped by, tapered portion 289 of tubular post 280. In this embodiment, a small protuberance of braid 104 extends radially outwardly and axially beyond tapered portion 289.
FIG. 9 shows the connection between coaxial cable connector 210 and the cable 100 in the completed, i.e. fully installed or fully compressed, state, wherein the tubular shell 220 (and the coupler 250) is advanced axially forward to surround at least a part of tubular post 280 and cable 100. No further crimping or manipulation is required after tubular shell 220 is fully advanced. Upon advancement of the tubular shell 220, jacket 105 and braid 104 are preferably sandwiched between the tubular shell 220 and the tubular post 280, shown in FIG. 9 where internal surface 222 and flat surface 287 of tubular post 280 sandwich jacket 105 and braid 104. In some embodiments, a portion of braid 104 is disposed in an annular cavity formed between the inner surface of the tubular shell 220 and the outer surface of tubular post 280, and preferably seized therebetween, for example as seen in the annular cavity 298 shown in the embodiment of FIG. 9. Trapping and seizing of braid 104 within such annular cavity as cavity 297 can provide additional and improved electrical grounding and improved mechanical retention of braid 104 thereby improving electrical and mechanical communication between cable 100 and coaxial cable connector 210. Lip 296 can serve to both position (for example, center) and restrain further axial movement of cable dielectric 102 with respect to the tubular post 280.
As the tubular shell 220 is moved relative to the tubular post 280, the third rearward facing tapered portion 297 engages the forward portion 223 of the tubular shell 220, causing the deformable lip 229 to be moved radially outward and into the annular recess 260 of coupler 250. The frontward facing surface 261 of coupler 250 then engages the rearward facing surface 230 to prevent the coupler 250 from sliding off the coaxial cable connector 210 in the forward direction, but still allows, if so desired, the coupler to rotate relative to the tubular shell 220 and the tubular post 280.
After the shell 220, post 280 and coupler 250 are installed on cable 100, the resulting connector/cable combination, or assembly, can then be placed into contact with a terminal, such as a threaded terminal. Using the advantage found in increased exposure area E2 the coupler 250 may be tightened onto the threaded terminal for electrical and mechanical coupling of the coaxial cable 100.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Thus it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
Patent Application
20080032551
